Many of the cigarettes currently distributed in the marketplace are manufactured by method called an “American Blend” method. This manufacturing method adds a large quantity of casing flavor to burley leaves as raw material, dries the leaves with a multiple-chamber dryer, and blends them with other raw materials. The process of adding the casing flavor to burley leaves and the subsequent drying process are called special processing treatment, which creates distinctive sweet odor and taste. The sweet odor and taste serve as chief aroma and flavor of “American Blend-type” cigarettes.
The special processing treatment, however, requires fairly large-scale equipment including the multiple-chamber dryer used for the drying process. The setup of an installation space and a large equipment investment are therefore necessary. The special processing treatment also requires high running costs. In addition, tobacco factories with no equipment for the special processing treatment have to entrust the treatment to other tobacco factories, leading to a deterioration in productivity.
International Publication WO 2004/107885 discloses a tobacco mixture having a reduced percentage of nitrosamine (TSNA) that is contained in leaf tobacco using burley leaves, and also discloses a cigarette containing this mixture. The tobacco mixture and the cigarette (leaf tobacco) containing this mixture are for producing American Blend-type leaf tobacco by preparing an absorbing agent for absorbing TSNA, and using 50 percent or more of the reconstituted tobacco flakes previously contacted to the absorbing agent. In result, leaf tobacco containing reduced TSNA is supposed be produced. However, since International Publication WO 2004/107885 adopts the American Blend method for manufacturing leaf tobacco, the special processing treatment is applied to manufacture the leaf tobacco. There still remains the problem that the special processing treatment is required.